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Show "ECONOMICAL DiSTRiBUTION OF IRRIGATION WATER By L. M. WINSOR, Utah Aflrlcultural College. Oregon Short Line Railroad Demonstration Demon-stration Truin Iecture. Accordlug to many historians. Irrl gatlon Is one of the oldest applied arts; one writer even claims that It la made a distinctive feature of the middle status of barbarism. Ancient Egypt became the granary of the f orld an a result of natural Irrigation through the Overflowing of the Nile; through Irrlgutlon Chaldea, Assyria, and llabylonla, located aa they were m a practically ralnleas country along the valley of the Tigrla and Euphrates, Euph-rates, rose to enviable prominence and dominion. The Chinese, the Humana nd the Moors, all made use of Irrigation. Irriga-tion. In this country we find evidence of It as practiced by the ancient Inhab Hants of this continent and later In the gardens of the old mission fathers of southern California, Numerous other examples to prove the Importance Import-ance of Irrigation as a factor In nation na-tion building might be cited; but to the Anglo Saxon race the art had Its birth but little more than half a cen-"iry cen-"iry ago. This aeema doubly strange when we look into history and find that at 1 lila time over 138.0uo.oo0 acres of land bad been reclaimed by Irrigation Irriga-tion in different parts of the world Perhaps this can be explained on the theory that the Germanic: peoples have always written history much faster than they have read it. However this may be, the first at tempt by the Anglo-Saxoim to reclaim re-claim the arid wastes of land was made In the summer of 147, In the Salt Lake valley by a little band of Mormon pioneers. To them we owe the birth of the modern art of Irrigation, Irriga-tion, and the working out of the co operative system as we have It In practice today. The Irrigation contagion soon spread and became not only the governing gov-erning factor In the establishing ot Mormon towns, but In the colonizing of the entire arid west. Irrigation as an art falls Into two divisions: 1st. Irrigation as a primary art, and 2nd. Irrigation as a secondary art. By the first we mean the using of Irrigation to take the place of cultivation, cultiva-tion, fertilization, and o on; and by the second we mean the using of lr; rlgatlon water merely to supplement the natural precipitation. The lattet Is the correct use of irrigation. If t farmer uses dry farm methods alonji with bis practice of Irrigation he can not go far wrong. One of the grave mistakes made b our early Irrigators was the India criminate use of water, with the re suit that thousands of acres of once productive land have been rendered Into veritable swamps, and alkali beds. The lamentable feature of this question Is the fact that with our sixty odd years of experience some of our farmers are still following these erroneous methods, and are ruining not only their own farms but those of their unfortunate neighbors, by a too liberal and careless application of water. This la especially true In some of the newer sections where a more or lens heavy application Is needed for the first few years. The tioub'e Is (hat they do not "set the brakes" until It Is too late. Once a new soil has been moistened below the ranee of the plant roots It needs a great deal less water than It required to begin with, the actual amount for the mi (urlng of any certain crop will vnry only with the seasons, cultivation, and so on being the same. This being the case It Is pontile to make an econ omlcnl distribution of the wa'er ai one's disposal and use It In a way which will not be detrimental to the soil and In a way to result In the greatest returtw to those concerned. This question Is one of prime Import anew to the farmers In this arid region and too much stress cannot be laid upon It. Situated as we are In a section where the rain and snow fall la very low, we are dependent almost abso lutely upon Irrigation water to In crease our agricultural possibilities The farming lands are almost unlimited unlim-ited within the border of our states, but there Is a decided limit to the water supply. The question then. Is not how much land have we? but how much water have we at our dls posu! ? The State of t'tah represents an area of over s2.0n) square miles, of which only 1.7"0 square mile are cu'-tlvated cu'-tlvated and less than I '" apiar miles or slightly undT 1 25 per cent of the total are actually Irrleated fldaho Is In a similar condition.) What we need then moit of all Is a distribution of ih water in such a way that the rrentefif possible re turns ran tie obtained The problem is not difficult of solution If we ontv apply ourselves to a sludr of conditions condi-tions as we find them and to the In-formation In-formation available. In the short time at my dltiosal I hope to open tip Sine of thought which will help some of you In your work; for, after I all, each of your Individual problems must be solved by yourselves. The amount of plant growth la de pendent In a decided measure upou the amount of moisture, within certain cer-tain limns, In the roil. The supplying and maintaining of thra moisture la an amount which will bring the greatest great-est return la, then, our problem. The water found In soils Is of thre kinds: 1st. Free water or the watei found hctwecu tbo soil particles of a saturated soil. 2nd. Capillary water or that which Is held In a thin film around each of the soil particles of a moist but not saturated soil. This Is the water UBed by the plant In Its growth. 3rd. IlygroHcoplc water which Is the water held by the soil but which, In all probability, Is not used by the plant. Only aqueous or water plants can grow In a soil containing free water. Hence our problem Is confined to the regulation of the capillary water only, and to the conditions which govern plant growth. There are three ways by which soil moisture can escape: 1st. Hy sinking Into deep soils out of reach of the plant roots, and escaping escap-ing by under drainage. 2nd. Uy evaporating from (he surface sur-face 3rd. Py passing through the plant Itself In a process known as transpiration. trans-piration. Fach of these losses can be governed gov-erned to a certain extent. The first by making lighter applications of water at each Irrigation. The second, or surface evaporation, can be checked check-ed by cultivating the surface sufficient suffi-cient to form a dust mulch, thus closing clos-ing up the opening of the capillary tubes which form when the surface soil begins to dry out. And the third or transplratlou can be checked by the addition of Bofl fertility or by ordinary or-dinary cultivation. Thus, the last two can Ih) governed by the vlmple opera tlon of stirring the surface after au irrigation. The thought is prevalent among farmers that a certain amount of water must be used by a plant In order or-der to produce a certain weight of dry matter. As early as 1090 Woodward found that It required less water to produce a pound of dry matter In a plant growing In a rich soil where the plant fond was evenly balanced, than In one of oiHslte nature. Later, in 1H7S, a German Investigator found that the yield of dry matter was greatest where transpiration was least. He also found that the enriching enrich-ing of the soil enabled the plant to produce dry matter with les water. Now the question may arise In your minds: Why should cultivation de-. de-. crease the amount of water actually used by the plant? Cultivation per 1 mlts the air and sunshine to enter tlrd ' soil more readily, causing a conse quent liberation of plant food, which la equivalent In effect to the addition - of the food artificially. That cultivation actually decreases . the amount of water used by the plant Is shown In the rsults of experiments ex-periments conducted at the 1'tah ex perlment station In the vegetation house. Certain tanks were planted to corn. An equal uumber of tanks containing con-taining the same kinds of soli were left haro for a check on the evaporation evapora-tion from the surface. Forty-eight hours after each irrigation and then every week, half the surfaces were cultivated while the other half were left bare. Table No. 1 shows the results. re-sults. TABLE NO. 1. Cultivation vs. Transpiration. Aver-age Aver-age for Three Years. I'iummI- waler Klndiof Cultivation ""c, ,f e. ii lo ,ro(Jtn I " It. dry mailer 71 hours afief College I Irrigation 252 loam ' Then Weekly I None C03 j 4H homs a'ler Fnmple Irrigation - Clay j Then Weekly I None IZj ; IS hours afier j Irrigation &&2 Clay Th,.n weekly I None 7u5 As the soil In each set of tanks was alike, and as all other conditions except ex-cept the cuttlva'lon were Identical It neecHSiirily follows that the reduced amount of water required to produo a pound of dry matter In the cultivated cultivat-ed pot was due to the cultivation and it (-fleets. There Is, then, a double reason for cultivating your crops. You not only hold the moisture In the soil by preventing pre-venting evaporation from its surface, but you make It possible for the moisture mois-ture retained to produce In some In-stnuees In-stnuees more iban twb-p aa much plant growth. This means that by the practice of cultivation you can make your irrigation water cover Just twice as much ground There la a marked variation In thf amounts (if water required for different dif-ferent varieties of plant. For exam-I exam-I pie. a'l other conditions being equal, (the potato plant requires more than itwo and one half times the water to 'to produce n pound of dry matter that the corn plant requires. (To be Continued ) |